The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for improving design routability by finding portions of an integrated circuit design where multiplexer structures may be introduced to improve routability.
One aspect of modern electronic design automation is the performance of logic synthesis operations. Logic synthesis is the process by which an abstract definition of a desired circuit behavior, which may be provided as a register transfer level (RTL) specification or the like, is converted into a design implementation in terms of logic gates, wirings, and other circuit design elements. Many examples of mechanisms for performing logic synthesis operations are available including hardware description language (HDL) based mechanisms, very high speed integrated circuit (VHSIC) hardware description language (VHDL) based mechanisms, Verilog based mechanisms, and the like. The mechanisms can be used to generate various types of integrated circuit designs including general purpose integrated circuits, applications specific integrated circuits (ASICs), and the like.
An application specific integrated circuit (ASIC) is an integrated circuit device that is designed to perform a particular specialized function rather than being of general purpose, such as a general purpose central processing unit or the like. For example, many communication devices today utilize ASICs that are designed to perform specific communication operations. The design of such ASICs usually involves a large number of signal communication paths on the chip as well as many crossbar logic structures. A crossbar logic structure, or crossbar latch, is a circuit element that is comprised of a signal line crossed by two control lines which, depending on the voltages sent down the various lines, can simulate the action of an AND gate, OR gate, and/or NOR gate (see U.S. Pat. No. 6,586,965 for more information on crossbar latches). The logic synthesis of such crossbar logic structures and the like often introduces complexities into the integrated circuit design that makes it difficult to perform placement and wiring operations, i.e. physical synthesis.